1. Field of the Invention
The present invention relates to a surgery-assistance apparatus, method and program to assist doctors in determining excision regions in surgeries of organs, such as livers and lungs. Further, the present invention relates to a computer-readable recording medium that stores therein the surgery-assistance program.
2. Description of the Related Art
When a surgery is performed on a patient to remove a diseased part (affected part) of his/her organ, such as a liver and a lung or lungs, doctors need to appropriately determine a part to be removed, in advance, by performing diagnosis using images before the surgery.
Japanese Unexamined Patent Publication No. 2007-054147 (Patent Document 1) proposes a surgery-assistance apparatus. In Patent Document 1, blood vessels, a liver parenchyma, and a tumor part are extracted from an X-ray CT image of the liver of a patient. Further, a blood vessel that dominates a region to which the extracted tumor belongs is identified based on the positions of the core lines of the extracted blood vessels, the diameters of the blood vessels or the like. Accordingly, a blood vessel that supplies nutrition to the tumor is identified. Further, in the region dominated by the identified blood vessel, a region in which a relative distance between pixels constituting a blood vessel and pixels constituting the liver parenchyma is longer than a predetermined maximum relative distance value is displayed as an abnormal perfusion region that might have been erroneously identified due to a mass effect on the blood vessel or the like.
Meanwhile, even if a target region to be removed is determined before surgery by performing diagnosis using images, a margin region is generally added to the target region in a real surgery, and both of the target region and the margin region are removed. The size of the margin region added to the target region has been determined based on a judgment by each doctor. Doctors need to make such judgments every time of surgery, and that is time-consuming and imposes more work on doctors. Further, since such judgments differ among doctors, it has been impossible to determine appropriate margin regions in a stable and efficient manner. Therefore, regarding the size of a margin region to be added to a target region, a technique for assisting doctors by a computer is also requested.